Gun support



Aprii 8, 194i. AjDEWANDRE 2,237,930

GUN SUPPORT Filed oef. 4, 1937 a -shets-sheet l1 a4 v y 64a 'J6 ma .93 v 27 l l 9 6 70 l aa //l n 69 10a .fw 46 101 Ja .sa n [5 f 4' I @Ll 29 In: i g' 62 26 73 -57 Z 35 .11'. v 56 3 /47- DGM/and@ /Nvrfw ar 52 April s, 1941.

A. DEWANDRE @un surronr Filed oct. 4, 1957 8 Sheets-Sheet 2 April 8, 1941. A. DEWANDRE GUN SUPPORT Filed Oct. 4. 1937 s sheets-sheet s April. s, 1941. A DEWANDRE. 2.237.930

GUN SUPPORT Filed Oct. 4, 1957 8 Sheets-Sheet 4 PY 8, 1941- A. DEWANDRE 2,237,930

GUN SUPPORT Filed Oct. 4, 1957 8 Sheets-Sheet 5 April 8, 1941. A. DEWANDRE GUN SUPPORT Filed oct. 4, 1937 8 Sheets-Sheet 6 FIG. 7?.

April 8, 1941. A. DEWAN DRE GUN SUPPORT 8 Sheets-Sheet 7 Filed Oct. 4, 1937 April 8, 1941. .A. DEWANDRE l GUN SUPPORT Filed oci. 4, 1937 s sheets-sheet a new mum,

Patented Apr. 8, 1941 GUN SUPPORT Albert Dewandre, Brussels, Belgium, assigner to Servo-Frein Dewandre, Socit Anonyme, Liege,

Belgium Application October 4, 1937, Serial No. 167,312 In France October 8, 1936 4 Claims. (Cl. 89-375) gun laborious and diilicult to him, more spepially at high altitudes.

To materially reduce the operators exertion, use may be made of a driving medium which may consist, inter alia, of compressed fluid, and the`l said fluid may be caused to act upon the various devices so as to eiect the rotary motion of the gun support around an axis and the lifting motion of the said support above the horizontal. 'I'he two movements may be effected slmultane- `20 ously.

My invention has for its object to provide a gun turret in which the rotary and elevatory movements of the gun operated by the gunner acting upon the gun proper are brought about by means25 of motors driven- -by fluid under pressure and which are automatically started by the action of the gunner.

According .to my invention, rotary motion of the gun ring around its axis is performed lbyjo means of motors or drive devices acting under the effect of fluid under pressure andI automatically operated when the vgun is displaced later'- ally, the actuation of the said drive devices and their speed of operation depending upon the amplitude of the lateral displacements imparted to the gun, -by the operator, with respect to the neutral position thereof.

On the other hand, lifting motion of the gun, which is supported upon an arch pivoted to the gun ring, is performed by hydraulic jacks com\l munlcating with a source of hydraulic fluid under pressure through interposed distributors automatically controlled by the relative movements of the gun with respect to the' gun support, eiectl 4 5 ed in the vertical direction.

My invention also comprises automatically cony trolled means for applying pressure to the liquid actuating the various hydraulic drive devices.

Various embodiments of the invention will be hereinafter described simply by way of example,V with reference to the -accompanying drawings, in which:

Fig. 1 is a diagrammatic plan view of a gun support comprising operating means according to one embodimen-t of the invention;

Fig. 2 is a diagrammatic section of the lifting mechanism for .the arch supporting the gun, in accordance with 'the said embodiment of .the inventiqn; 1, '.1 6,0

Fig. 3 is a diagrammatic part sectional view. drawn to a larger scale, of the mechanism adapted'to produce the rotary motion of the gun ring A around its axis as shown in Fig. 1;

Fig. 4 is a detail view of the mechanismshown `in Fig. 3;

Figs. 5, 6 and 7 are sectionalviews of a quickacting fluid escape-valve of .the device, showing diierent positions of the said valve;

Fig. diagrammatically shows a pulley system used to secure the required amplitude of angular displacement of the gun ring Fig.- 9 diagrammatically illustrates the mech- Aanism for controlling and raising the arch shown 4in Fig. 2;

'Figs-l0 is a part sectional view, drawn to a larger scale, of the control system for the lifting mechanism ofthe arch according to Fig. 2;

Fig; 11 is a diagrammaticsectional view of the oleo-'pneumatic pump as applied to a modiiied embodiment of the invention; I Fig. 12 is a diagrammatic plan view partly in section showing the arrangement of the means for operatingthe rotation of the gun ring by the action of oil under pressure.

Fig. 13 is a diagrammatic elevation of a modied embodiment of the arch lifting mechanism. comprising a distributing systemfor the oil under pressure;

Fig. 14 is a diagrammatic vsectional view, drawn 'to a larger scale, of the distributor valve controlling ythe flow of oil under pressure in Ithe roi 'tating and lifting cylinders;

Fig. 15 is a diagrammatic view of a further modification of the rotating mechanism operated from a motor driven by oil under pressure;

Fig. 16 is a diagrammatic view partly in section of the valve controlling the supply of oil undegr pressure to the motor for rotatlngthe gun ring.

As shown in Figs. 1 and 2 of the drawings, the gun support comprises a xed circular portion l5 secured to the aeroplane and a movable portion I6 diametrically and horizontally guided by means of rollers I1, as is known per se in the construction of turntables.

Pivotally mounted about the central portion of an arch l-which is in 'turn pivoted at I9 to the movable part I6 of the gun supportthere is a fork 20 universally supporting the gun 2l.

Two drive cylinders 22 and 23 made rigid with the fixed part I5 of Ithe gun support are adapted to act each separately to impart to rthe movable member I6 a rotation in either direction'under the effect of the movement of the pistons 24 and 25 mounted in the' said cylinders and through the medium of a combined system consisting of ca- .bles 26 and 2l and pulleys 28 and 29.

The said cables are guided in grooves formed `on the lperiphery of the movable member l, e acli cable having one of its ends secured to the said movable member at 39 or 3l respectively, while the other ends of the cables are secured. one. at

3 2, to a member 34 provided at the end of the piston rod 35 of the piston 24, and one, at 33, to a member 35 provided at the end of the piston rod 31 ofthe piston 25.

To obtain a suiiicient amplitude of angular movement of the gun ring while avoiding the use of drive cylinders of impractical length, -the invention provides increasing the 'amplitude of the peripherical movement of Ithe gun ring with respect to the amplitude of .the longitudinal movement of the piston of the drive device by means of a pulley system interposed in the path of the cable and consisting of pulleys, part oi which are pivoted to fthe end oi the piston rod, and part to the drive cylinder (Fig. 8) r To control the motor cylinders there are provided two twin distributors 35 and 39 supported by the arch I9 and adapted4 to put in communication the drive cylinders 22 and 23 with the compressed air supplied from a reservoir (not shown) and entering the said distributors through the duct 49.

Each distributor comprises a valve 4l normally applied on its seat by the action of a spring 42 and actuated by the longitudinal displacements of a hollow .stem 43 movable against the opposing action of a spring 44 so as to drive back the said valve thus opening the communication between the fluid supply duct 45 and the discharge orifice 45 of the fluid to the drive cylinder.

A pipe 45a connects the distributor 35 with the cylinder 23, while a pipe 45h connects the distributor 39 with the cylinder 22.

'I'he distributors 39 and 39 are operated by the relative displacements of the gun with respect to the axis of the fork 29.

To this end, the said fork is fitted laterally with a linger 45 the end portion of which is movable, with a convenient play, betweenthe limbs 41 and 48 of a U-shaped member integral with a rocking lever 49 pivoted on the said distributors at 59.

It will be easily understood that every time the gunner imparts to the butt of the gun a lateral movement of convenient amplitude in the one or the other direction, this will be effective in displacing the 'finger 49 in the same direction, which finger will act so as to rock the lever 49 tion or may consist for instance of a body 51 having-mounted therein an eccentric plug 59 movable through the medium of a lever 5l, the said plug being adapted, when in the normal position, to close one of the oil admission or escape apertures, while, in moving in the one or the other direction, the said plug progressively uncovers the said aperture.

The valve 55 is operated from the movements of the rocking lever 49 and, to this end, the inventi'on provides for means whereby the operation of the said valve is caused to slightly lag behind the opening of the distributor 35 or 39.

'Ihe retarding means consist in forming the lever 49 with recesses 59 and 5l having inserted Vtherein springs 52 and 53 acting upon brackets 54 and 55 pivoted to the fulcrum 59 and having the extent of their movement limited by pins 85 and 51.

with a resulting actuation of the one or the other distributor, thus opening the communication between the source of iluid and one of thev drive cylinders.

However, a deviceso designed would not be capable of securing the required accuracy in the displacements of the gun ring, as regards both the quick displacements of great amplitude and. u

the small displacements.

According to the invention, the required precision is obtained by arranging the drive pistons 24 and 25 so that they move in one with two pistons 5l and 52 mounted to slide in'cylinders 53and 54 respectively. The' latter cylinders are connected with each other through a pipe 55, and

the chamber thus constituted between the faces of the two pistons 5| and 52 is filled with oil.

The pipe 55 has interposed in it a throttle valve 55 supported on the arch i8 and adapted, according to its position, to cut oi or to regun late the flow oi! oil caused to pass from one cylinder to the other when the pistons 5l and 52 move in opposite directions.

'lhe valve 55 may be of any suitable constructributors 35 or 39-'inasmuch as the elastic rel sistance of the springs 62 and 53 is greater than the combined elastic resistance of the springs 42- and 44.and further, in'opening the throttle 55 through the medium of the link 55 pivoted at one end to the lever 49 and at the other end to the lever 55.

Thus. when one of the distributors is opened as a result of an initial lateral shift of the gun around its pivotal axis. no movement of the gun ring will take place, considering that the valve 55 will still remain closed. The communication between the two oil cylinders 53 and 54 will not be opened unless an additional lateral impulse is imparted to the gun. The greater the extent of lateral shift of the gun with respect to its support, the greater the cross area of oil ilow and, consequently, greater the speed of movement of the gun ring.

To secure the closure of the valve 55 after the gun has returned to its neutral position, /the lever 49 is connected through a rod 69 to a drive back system 10 comprising a neutraliser spring 1I and acting so as to move back the distributors and the said valve to their respective positions of rest and to keep them in these positions under acertain bias.

To allow the rotary motion of the gun ring to be suddenly reversed, the invention makes provision of quick discharge valves 12 and 13 each mounted at the intake aperture of the drive cylinders which are shown in detail in Figs. 5 to Each of the said valves consists of a casing 14 comprising a cylindrical chamber 15 having mounted therein a piston 15 capable of a limited sliding stroke.

The head of the piston 16 bears a valve member 11 the stem 18 oiwhich is guided axially inthe said piston and carries at its lower end a second valve member 19, the valve member 11 being normally applied on its seat by a spring When in the inoperative position, the valve member 19 closes an aperture 8l provided for the escape of uid to the atmosphere and formed inthe casing 14. The latter also comprises an aperture 82 connected with the fluid supply pipe,

and an aperture 83 communicating with the chamber formed inside the corresponding drive cylinder. l/

The inpperative positions of the valve members 11 and 19 is shown in Fig. 5. When iluid under pressure cancelled by the twin distribthe latter away, thus opening the communication between the fluid supply pipe and the interior of the drive cylinder (Fig. 6).

When the pressureis relieved in the duid supply pipe the piston 16 is returned by the action of the air under pressure contained in the drive and 19, thus uncovering the aperture 8| with a resulting quick escape of the air under pressure to the atmosphere (Fig. '7).

` To produce the angular displacements of the arch I8 (Fig. 9) around the fulcrums I9 provided 15 at the movable part I9 of the gun turret, thus allowing the gun to be raised and lowered, the invention provides two hydraulic jacks 88 and 84a pivoted at the one hand, at 85, to the movable part I9, and on the other hand, at 88, to

the arch I8, in a recess 81 provided in the latter.

The said jacks are connected through a pipe 88 with the discharge of an oil pump 99 comprising a piston 99 the piston rod 9| of which is operated by a further piston 92 slidably mounted 25 in a drive cylinder 93 and actuated by compressed air.

The operation of` the pump 89 is controlled by a compressed air distributor 99 similar to the distributors 38 and 39, the distributor 9d being 30 supported by the arch I8 and coupled with a valve 95 controlling the blow-oil from the jacks 89, 84a and the re-flow of oil to the cylinder of the pump 89.

The distributor 9B and the valve 98 are auto- 35 matically operated when a relative vertical mntion is imparted to the gun with respect to its support. To this end, a. recessed member 96 (Fig. 10), provided inside with two abutment surfaces 91 and 98, is pivoted at 99 to the end of a pro- 40 jection IBI) extending from the said member 98.

The member 98 is caused to move angularly around its pivotal center 99 when the gun is displaced vertically, the member 99 being connected to the said gun by means of a link IDI.

When thus moved angularly, the member 98 comes to act upon one of the ends of an oscillating lever |02 pivoted at |99 to the control distributor, so as to open'the air distributor 9d when the butt end of the gun is being lowered 5U with the object of raising the barrel. Opening the distributor 96 is eiective in establishing the communication between the source of compressed air IUd(Fig. 9) and the cylinder 93, through a pipe |95.

Under the action of the compressed air, the piston 92 is caused to move and takes with it the piston 90 which forces the oil from the cylinder 89 into the :lacks 94 and 86a, thus causing the arch I8 to rise. 60 As soon as the line of sight is reached, slightly y pump, under the effect of the weight of the gun,

when the air pressure is relieved from the piston 92, provision is made of va check valve |08 inter posed in the pipe Y89, at the discharge orice of the pump 89.

When the distributor 954 is closed, theair contained in the cylinder 93 is allowed to escape through a quick discharge valve -Il'similar to the valves 12 or 18. L

To produce the downward movement of the arch, all that need be done is to raise the butt of the gun-thus lowering the barrel-which will be eective in rocking the lever |02 by means of the link IOI and the member 98, with the result that the valve 98 will be opened and the oil cylinder and takes with it the valve members 11 10 contained in the jacks will return to the pump 89 through the pipe |08 which has interposed therein, at |09, a check valve adapted to prevent the oil from passing through the said pipe when the pump 89 is operated.

The rotary movement of the gun ring and the vupward and downward movements of the arch may be simultaneously produced by the operator in imparting to the butt of the gun an oblique movement so as to simultaneously act upon the two rocking levers 49 and |92.

In the above-described embodiment the rotary as well as'the elevatory movements of the gun involve-whatever be the amplitude of such movements-a complete lling up of the cylinders working on compressed air, while, when thev movement concerned is arrested, the compressed air is to be completely drawn oif from the said cylinders. Consequently, the device, when so designed, results in a high consumption of compressed air for a series of small displacements. The quantity of air thus consumed is not a function of the displacements of the gun ring.

To reduce the said air consumption so that it be exactly proportional to the movements imparted to the gun, a modified embodimentof the invention may be designed, in which the driving medium used for rotating and raising the gun support members consist of oil put under pressure by means of an automatically operated oleopneumatic pump.

According to the modied embodiment, the oil under pressure is delivered through the pump shown in Fig. 11, in which IIII and IIIJA indicate the compressed air cylinders. Forming extensions of the cylinders III), IIA, there are provided two cylinders III and IIIA in which the oll is set under pressure. In each pair of cylinders IIU-I II and IIUA-I I IA there is slidably mounted a pair of pistons II2-II3 or II2A| I3A, the pistons of each pair being interconnected by ,piston rods IIB and IIGA respectively. The said pistons are urged to their respective positions of rest by means of the springs IIB and IIEA. That portion of the cylinders which is comprised between the pistons II2 and H3, and IIZVA and H3A is constantly in communication with the atmosphere through the apertures IIS and IIA.

At the bottom ofthe cylinders I I I and IIIA there are provided balls or valve members II1 II8 and II1A--I I8A,which are applied against their seats by springs IIS-|29 and HSA-INA. An oil:f tank I2I is adapted to collect the re-flow oil discharged through the pipe |22. On the other hand, the compressed air from the cylin/ ders IIB and IIIlA is allowed to escape to the/ atmosphere through the pipe |23. To assist the oil in entering the cylinders III and IIIA, air pressure is formed initially above the oil level in the upper portion oi' the tank I2I, which thus acts as an air chamber, and the said pressure may be automatically maintained`by any convenlent means.

The compressed air distributors are of the type disclosed in United States patent application Serial 124,096 and consist of castings |21,A |21A formed inside with chambers |28, |28A provided with vextensions which constitute cylinders |29, |29A sealed at their outer ends by plugs |30 and |30A and communicating through apertures |3| and |3|A with a pipe |32 connected with the source of compressed air or tank |33. The now from the said source may be shut out by means of a cock |34 interposed in the pipe |32.

In the cylinders |29 and |29A there are slidably mounted valve members |35 and |35A car- `ry'ing each on its head axpacking |38, |38A of elastic material. The valve members |35, |35A are applied against their respective seats by the springs |31, |31A and by the pressure of the compressed air flowing along the said valve mem'- bers. heads of the valve members |35 and |35A extend across the chambers |28 and |28A and are connected to valve, membersI |39 and |39A arranged to slide in bores |40 and |40A provided inline with, and forming extensions of the chambers |28 and |28A. The valve members |39 and |39A are connected to pistons |4| and |4|A by means of rods |42 and |42A and through the medium of elastical washers |43 and |43A.

In bores |44 and |44A situated at right angles tothe casings |21 and |21A of the distributors and extending from one. side to the other of the said casings, there are slidably mounted bolts |45 and 45A, one end ci' the said bolts being subjected to the action of the compressed air in the chambers |46 and 48A, and the other end to the opposing action of the springs |41 and |41A. The bolt members are formed each with a restricted portion, the latter portions being provided with openings |48 and |48A arranged |29, |28, passes through the pipe |53 and enters the chamber inside the cylinder |0 where it acts Stems |38 and |38A secured axially in the to allow the valve members |39 and |39A to pass therethrough.

Plugs |49 and |49A are adapted lto seal the ends of Ithe casings |21 and |21A and to form chambers |50 and |50A. These chambers are connected through pipes |5| and |5|A with the apertures |52 and |52A provided in the compressed air cylinders ||0 and 0A and so arranged as to be uncovered, one at a time, every time one of the pistons ||2 or ||2A reaches the left handend (Fig. 11) 'of its stroke. The chambers |28 and |28A are connected to the bottoms of the cylinders ||0 and ||0A through pipes |53 and 53A, respectively. A

Moreover, the chamber |50 is connected with the chamber |48A through the pipe |54, while the chamber |48 is connected with the chamber |50A through thepipe |55. Finally the chambers and |40A communicate with each other through the pipe |58, which is in turn connected with the pipe |23 for the escape of compressed air.

The plug |48 has slidably mounted therein Va.

push button |51, and the end of the said push."

button protruding into the chamber carries a valve member |58 which is applied against its seat by Ythe spring |53. 'The push button |51 is intended for effecting theinitial start of the device. The operation of the device is as follows: When the device is in the position illustrated in the diagrammatic Fig. 11, the air under pressure flows out of the' tank |33 through the pipe |32 and enters the chambers |28 and |23A upon .the 4piston ||2, The latter piston, by means of the rod ||4, takes with it the piston I3, which in turn acts upon the oil contained in the cylinder lli. the ball and flows to the drive devices.

While the piston ||3 is moving to the left, the pistons ||3A and ||2A are returning to -the right under the action of :the return 'spring ||5A and the cylinder |||A is filled up, through pipe |8l, with oil from the oil tank, which oil is drawn into the said cylinder with the assistance of the pressure exerted upon the surface of the oil contained in the said tank. The compressed air escapes from the cylinder ||0A through the pipe |53A, the chambers |28A and |40A and the pipes |58 and |23.

When the piston ||2 reaches the left hand end of its stroke, the aperture |52 is uncovered and the com-pressed air passes through .the pipe |5|A into the chamber |50A of the distributor. At this moment the piston |4| is moved under the action of the compressed air and applies the valve |39A on its seat. Hence, the `p0rt |80A Ls uncovered and the compressed air flows through the pipe |55 and enters the chamber |46 so as to act upon the Vbolt |45, thus freeing the valve |38 which is therefore lifted from its seat under the action of the spring |31. At the same time, the valve |38 is applied against its seatand cuts oif the ilow of compressed air to the cylinder H0.

On the other hand, the action of compressed air upon the piston IIIA has been eiective in applying the valve |39A on its seat and in opening the valve |36A, thus putting the source of compressed air in communication with the cylinder ||0A the piston I IZA of which has previously returned to the right hand end of its stroke.

It will be seen that the pressure .is not relieved when the flow of compressed air is reversed.

Thus, Ithe compressed air from the reservoir |33 enters the cylinder ||8A through tube |32,

through the apertures |3| and I3IA. .The valveV member |35A beingapplied on its seat, the compressed air is retained in the chamber |23A. Y

T he compressed port I3IA, chambers |40A, |28A and pipe I53A. At the same time, the air from the cylinder Ill) escapes through pipe |53, chambers |28, |48 and the pipes |58 and |23 .opening to the atmosphere.

On the other hand, oil from the oil tank enters again the cylinder through the pipe |8| in lifting the ball ||8.

When the piston ||2A reaches the left hand end of its stroke, the .port |52A is uncovered and the compressed air owing out through the said port is effective in starting the action of the distributors with the view of re'opening the com- -munication between the cylinder ||3 -and the source of'compressed air, in accomplishing the functions above described, The reciprocation of livered from the oleo-pneumatic pump above described or from any other pump device. To controlthe drive cylinders, provision is made of a combined distributor |82 comprising four needle valves and supported by the arch, the said airiiows acrossthechambers adlptedtoopenthecommuni- As soon as the oil is forced out it lifts seat by the action of springs |10, |1I, |12, |13..

The said needle valves are formed with a threaded .portion |14 which, upon rotary motion im-parted to the needles, acts so as to allow the progressive opening or closure of the communication with the pump, through delivery pipe |65, and of the communication with the oil tank IZI, through re-flow pipe |65.

Two pipes and |16 are provided Ato connect the distributor to the drive cylinders |63 and |64, respectively.

The distributor is operated, as in the precedcation between the drive cylinders |63 and |64 ing embodiment. by the relative displacements of the gun about the axis of the fork 20. To this end, the finger 46 of the fork 20 may be arranged to be movable, with a certain play, between the arms |11 and |18 of two levers rigidly secured to the needle valves 66 and |68, The arms |19 and |80 of the said levers are connected by links |83 and |84 to levers I 8| and |82 rigidly secured to the needle valves |61 and |69. The actuation of the needle valves |61 and |69 may be arranged to slightly lag behind the opening of Ithe needle valves |66 and |68, owing to the back lash |85 and |86 provided between the top ends of the levers |8|, |82 and adjustable stops secured to the links |83 and |84.

Every time the nger 46 is shifted laterally this will result in rocking the lever and link assembly |19, |83, |8| or |80, |84, |82 which in turn will be effective in opening the communication between the source of oil under pressure and one of the drive cylinders through the pipe |81, on the one hand, and in opening the communication between the other drive cylinder and the oil tank through the pipe |88, on the other hand.

To produce the angular movements of the arch I8 about the fulcrums I9 provided at the movable part I 6 of the support and to enable the gun A to be raised and lowered at will, provision is made, inaccordance with the embodiment last referred to (Fig. 13), of two hydraulic jacks |89 and |89A, said jacks being integral with the arch,

- and the piston rod |90 of the piston |9| of each f jack being pivoted at |92 to the movable part I6 conveying oil under pressure to the drive cylindersfor rotating the gun ring are now replaced by the pipes |93 and |94 which supply oil under pressure to the jacks adapted to raise and to lower the arch. `The device according to the invention therefore comprises two distributors identical to that described with reference to Fig. 14.

The distributor controlling the lifting movement is automatically operated when the gun is displaced with respect to its support. To lthis end, a lever |95 pivoted to the fork 20 at |96 is provided with a iinger |91 which is movable between the levers |11' and |18' of the distributor.

The nger |91 is angularly displacedwith respect to itsfulcrum point |96 when the gun is shifted vertically, the lever |95 being connected to the said gun by a link |98. When moved, the finger |91 comes to act upon the lever |11' and |18', which levers are rigidly secured to the needle valves of the distributor, the said action being .effective in opening the communication between the source of oil under pressure and either of the faces of the piston |9| of the jack |89 through one of the pipes |93 or |94. n

When one face of the piston ISI is in communication with the source of oil under pressure,

the other face thereof is in communication withr the tank |2| from whence the oil is re-circulated by the pump-as is the casein the drive cylinders operating the rotary movement of the gun ring.

- 'the operator imparts to the gun a pivotal movement in that direction, which results in displacing the finger 46, and the latter, in abutting the lever |11', opens the valve needles |66 and I 61, thus establishing the oil circuit through pipe |65, chambers |99, 200 and pipe |81, and the oil enters the drive cylinder |63. At this moment the pressure of the oil acts upon the piston 20| which effects the rotation of the gun ring through the cable 202.

At the same time, the oil from the drive cylinder |64 flows back to the reservoir |2I through pipe |88, chambers 203, 204 and pipe |22. To arrest the rotation of the gun ring, the operator stops pushing the gun and the needle valves and |61 are closed again under the action of the return springs |10 and I1I.

To perform a left hand rotation, the operator acts upon the gun so as to operate the valve needles |68 and |69, and the functions described in connection with the right hand rotation will be repeated.

The raising and lowering of the arch is ob tained by shifting the gu`n in the vertical plane. To raise the arch, the operator points the barrel of the gunupwards, which is effective in actuating the distributor in charge with the raising in such a manner as to open the-oil circuit between the pump and the lifting jacks. To lower the arch, the operator acts upon the gun so that the barrel is pointed downwards. The oil is then -circulated in the manner described above with reference to the rotary movement of the gun ring.

The rotation of the gun ring and the raising and the lowering of the arch may be effected simultaneously by the operator, as is the case in the first embodiment.

A third embodiment (Fig. 15) consists in that the rotation of the gun ring may be obtained from a volumetric motor operated by oil under pressure delivered by the pump.

To this end, the fixed circular part I5 of the gun support is fitted with a ring gear 205. The

movable part I6 of the gun turret has fixed thereto a motor 206 of a well known suitable reversible type, which is operable by oil pressure.

The shaft of the said motor has keyed thereon a.

pinion 201 adapted to'mesh with the ring gear 205. The motor'206 is connected with the distributor |62 through pipes |81 and |88.

v'Io producethe rotation of the support I6, the

In the arrangement illustrated in Figs. 12

l3--l5, the pump P is provided on a frame-208 integral with the movable part I6. The bottom of the i'rame may be furnished with a iloor 209 ior the operator. Under the iloor there is provided a rotatable socket joint 2|0 which may be v connected to a pipe conveying air under pressure from a reservoir.

'I'he lower portion 2|| of the interposed socket joint may be pivotally mounted with respect to the upper portion thereof, which is secured to the underside of the floor of the support. Owing to this arrangement, the compressed air cylinders of the pump may be connected with the source of compressed iluid by means of rigid pipes.

0f course, the pump may be located at any pointv of the aeroplane, in which case the connections will consist in ilexible pipes.

IThis applies also, in the case of Fig. 15, to the motor B operating the rotary movement of the gun support. The motor 208 may be mounted on the xed part I5, and the ring gear may be rigid with the circular movable part i6.

Instead of being produced from the relative movements imparted to the gun with respect to its support. the vertical and horizontal displacements of the said gun may be obtained by the aid of a lever independent on the gun and which may be caused to perform the same movements as that imparted by the operator to the butt oi the gun.

AIn such an arrangement, the trigger of the gun can be connected through a nexible transmission device to an operating member provided on the said lever.

Of course, any one of the rotating devices or of the raising devices according to the invention may be used independently, it is to say, that any desired gun ring rotating system may be combined with one of the arch raising systemsabove described, while, on the other hand, one oi' the above described systems for rotating the gun ring may be combined with any desired arch raising system.

It will be understood that the oleo-pneumatic ofv said air cylinders, a movable member in each o! said oil cylinders, each of the latter members being connected to one of the movable members of the air cylinders, cables attached to said movable ring for being controlled by the said movable members and for turning the said movable ring in opposite directions, guiding pulleys for the said cables, means for amplifying' the angular displacement, of the said ring relatively to the displacement of the said movable members, a conduit connecting the two oil cylinders, a valve for regulating the section of passage in the said conduit, means depending on the lateral displacement of the gun relatively to its support for controlling the air distributors and then the oil valve and for varying the speed of movement of the said movable members by reason of the lateral angular displacements of the said gun.

2. A gun support according to claim 1, characterized by the means provided for controlling the air distributors and then the oil valve by the lateral displacemnts of the gun on its support comprising an air distributor for each of the driving cylinders, an oscillating lever for alternately controlling one of the said air distributors, a fork on the said oscillating lever,

a pivoted support for the gun, means on the pump device above described makes it possible to Aobtain very Vhigh ratios of pressure transformanon. and owing to this feature tneapparatus A used to produce the various movements of the gun turret will be oi' very reduced volume and weight.

Moreover, the oleo-pneumatic pump system may be applied in any other plant using compressed air as power medium.

What I claim is:

i. A gun support comprising a xed ring, -a movable ring turning on the said fixed ring and a gun pivoted to the said movablering, two compressed air driving cylinders, a movable member in each of said cylinders, two oil cylinders veach of which is arranged parallel to one pivoted support for engaging the said fork with play, means including springs for maintaining the said lever in its normal position, a cylindrical shell for the oil valve, two diametrically opposed openings communicating with the cylindrical wall of the said shell, conduits for establishing the communication of each of said openings with one of the oil cylinders, an eccentric plug in the said shell for normally closing one of the said openings, a lever'provided on the said plug for being controlled by the said lever oscillating in the two directions of the angular movement of the latter under the action of the lateral displacements of the gun.

3. A gun support according to claim 1, characterized by means for turning the movable ring in' opposite directions by the displacement of movable members oi pneumatic motors comprising guiding pulleys supported respectively by the air cylinders and by the movable members of the said cylinders, cables for cooperatexternal cylindrical face of the said movable circle, and channels in said cylindrical face for guiding each of said cables on an.opposite side of said ring.

4. A gun lsupport comprising a iixed ring. 8 movable ring rolling over the said iixed ring, an arch pivoted to the said movable ring, a universal Joint for supporting the gun on the said arch, hydraulic jacks for raising and lowering the said arch, a driving air cylinder supported by the said arch. an oil cylinder supported by the said arch, a piston in each of the said cylinders, a joint for uniting the said pistons, and distributing means operated by the vertical displacements of the gun relatively to the said arch for driving the said motor and for controlling the admission of the oil to the said Jacks as' well as the return of the said oil to the cylinder of 

